1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a multi-domain liquid crystal display device in which a common auxiliary electrode is formed on a layer equal to a gate line to surround a pixel region and a dielectric structure is formed on a common electrode so that a viewing angle extends.
2. Discussion of the Related Art
Recently, a liquid crystal display device which drives a liquid crystal by an auxiliary electrode electrically insulated from a pixel electrode without aligning the liquid crystal has been suggested. Such a related art liquid crystal display device will be described with reference to FIGS. 1a and 1b. 
As shown in FIG. 1a, the related art liquid crystal display device includes a first substrate, a second substrate 33, a plurality of data lines and gate lines, a thin film transistor, a pixel electrode 13, a passivation film 37, and an auxiliary electrode 21. The data lines and gate lines are formed on the first substrate lengthwise and crosswise to divide the first substrate into a plurality of pixel regions. The thin film transistor is formed in each pixel region on the first substrate and includes a gate electrode, a gate insulating film, a semiconductor layer, an ohmic contact layer, and a source/drain electrode. The pixel electrode 13 is formed on the gate insulating film and the passivation film 37 is formed on the pixel electrode 13 including the whole first substrate. The auxiliary electrode 21 is formed on the passivation film 37 to partially overlap the pixel electrode 13. At this time, the pixel electrode may be etched in a specific form to form an open region so that the pixel region is divided.
The related art liquid crystal display device further includes a light-shielding layer, a color filter layer formed on the light-shielding layer, a common electrode 17 formed on the color filter layer, and a liquid crystal layer formed between the first substrate and the second substrate. The light-shielding layer is formed on the second substrate 33 to shield light leaked from the gate line, the data line, and the thin film transistor. An open region 27 may be formed in the common electrode 17 to distort electric field applied to the liquid crystal layer.
The auxiliary electrode 21 formed around the pixel electrode 13 and the open region 27 of the common electrode 17 distort electric field applied to the liquid crystal layer so that liquid crystal molecules are variously driven within a unit pixel. This is intended that a dielectric energy by the distorted electric field places a liquid crystal director at a desired position.
However, the liquid crystal display device requires the open region 27 in the pixel electrode 13 or the common electrode 17 to obtain multi-domain effect. To this end, the process for patterning the electrodes is additionally required.
Furthermore, if the open region 27 is not formed or has a small width, distortion range of the electric field required to divide the domain is weak. Accordingly, there is a problem that the time when the liquid crystal director reaches a stable state relatively becomes longer.